* from ftp://ftp.netbsd.org/pub/NetBSD/misc/gmcgarry/bench/syscallbench.tar.gz
*
* gcc -Wall -Werror -O3 -static -o ctx ctx.c
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <unistd.h>
#include <OS.h>
#define ITERATIONS 500000
static void
usage(void)
{
printf("syscallbench [-h]\n");
exit(1);
}
static int null_func(void)
{
return 0;
}
static unsigned long test_func(int (*func)(void))
{
struct timeval before, after;
unsigned long elapsed;
int i;
gettimeofday(&before, NULL);
for (i=0; i<ITERATIONS; i++) {
func();
}
gettimeofday(&after, NULL);
elapsed = 1000000 * (after.tv_sec - before.tv_sec);
elapsed += after.tv_usec - before.tv_usec;
return elapsed;
}
int
main(int argc, char *argv[])
{
unsigned long overhead;
unsigned long libcall;
unsigned long syscall;
if (argc > 1)
usage();
overhead = test_func(&null_func);
libcall = test_func((void *)&getpid);
syscall = test_func((void *)&is_computer_on);
printf("overhead time: %ld nanoseconds\n",
(1000*(overhead))/ITERATIONS);
printf("libcall time: %ld nanoseconds\n",
(1000*(libcall-overhead))/ITERATIONS);
printf("syscall time: %ld nanoseconds\n",
(1000*(syscall-overhead))/ITERATIONS);
return (0);
}
